Known tubular inflators for inflating gas bags in vehicles are usually configured single-stage or two-stage. The expense of their fabrication is relatively high, this being due to the fact that totally different designs are provided for single-stage and two-stage inflators. Tubular inflators are mainly provided for restraint systems on the front passenger side since their outer geometry is best suited for accommodation in the dashboard.
One highly complicated two-stage tubular inflator configuration is evident from U.S. Pat. No. 5,033,390. In this arrangement, at the two axial ends of the inflator housing combustion chambers are provided between which two expansion spaces are arranged. These two expansion spaces separated from each other are formed by two outer disks and an intermediate disk formed integrally on an anchor adjoining the outer disks. In addition to this, elongated tubes are screwed into place axially from without, which comprise a booster charge in their interior and are connected with axial covers which seal off the two-part tubular housing at the end faces. Moreover, the tubular housing has in its interior axial stops for positioning the disks. When an inflator is to be produced which has larger or smaller combustion chambers, the housing and anchor parts need to be redimensioned. This makes the use of like parts very difficult. It will also be readily appreciated that this complicated structure makes fabricating the inflator relatively expensive. On top of this the individual parts do not lend themselves to be also put to use in single-stage inflators. The same drawbacks are exhibited by the inflator disclosed in U.S. Pat. No. 5,219,178, in which all parts inserted in the tubular housing adjoin each other axially and fix each other in position.